/u/RiotTripoid Linux community would greatly appreciate any feedback here although I understand that Linux is not officially supported. In Wine environments this crash happens just after the start of "League of Legends.exe" and it happens due to assertion failure. Some details are available here https://github.com/kyechou/leagueoflegends/issues/83 if it'd help in anyway in narrowing the root cause that seems to also affect Windows users.
Hi, I know this is not an answer but we are actively investigating root causes for these crashes. I'll try to provide an update as soon as we find clear resolutions. If you want to DM me client logs I can relay them to the appropriate people, these live in the GameLogs directory.
Sorry for a half answer :/